what do do about utility theft?

[Jimmy Chao]

I have a spigot on the outside of my building, and the residents of the building next door keep stealing my water, despite having access to a spigot of their own. I have come up to the building multiple times to find then with a hose attached to my spigot. I bought a $20 spigot lock and thought that had fixed the issue, but when I pulled up yesterday the lock was gone and there was another hose attached. O can't figure out how the lock was removed.